1. Field of the Invention
The present invention relates to a printing apparatus and a printing method of which printing accuracy is improved without the complication of the structure of the apparatus, and more particularly, to a printing apparatus and a printing method that can be used to form a gate electrode, a source electrode, a drain electrode, wires, and the like of a thin-film transistor used in electronic paper and the like.
2. Description of the Related Art
In recent years, gate electrode, source electrodes, drain electrodes, and metal wiring of thin-film transistors and fine patterns, such as electrical wiring patterns, have been formed on a glass substrate, a resin substrate, or the like by using a printing method. A substrate on which fine patterns are formed with liquid containing conductive particles, such as metal, by a printing method is used in thin display devices, such as electronic paper and a liquid crystal display, a portable communication device, and the like.
In a pattern printing apparatus disclosed in JP2005-81726A, a thin resin layer is provided on a flexible metal flat-plate-shaped intaglio plate and an ink repellent pattern is formed thereon to form recessed portions. Ink is sprayed and supplied to the recessed portions from below by the ink jet of ink supply means. After the ink is supplied, a solvent is vaporized from the ink, which is present in the recessed portions, by ink drying means so that the ink is dried without losing viscosity. A printing target and the flexible metal flat-plate-shaped intaglio plate are positioned, and the flexible metal flat-plate-shaped intaglio plate is pressed by a press/release cylinder of ink transfer means while the printing target and the flexible metal flat-plate-shaped intaglio plate are made to roll. As a result, the ink, which is present in the recessed portions, is transferred to the printing target. After the ink is transferred, the flexible metal flat-plate-shaped intaglio plate is released while being bent.
JP2008-258249A discloses a pattern forming apparatus that is to accurately and easily form fine patterns on an object. In the pattern forming apparatus disclosed in JP2008-258249A, a substrate to be processed is placed on a stage and a first pattern forming unit acquires the position of a letterpress plate relative to a predetermined reference mark provided on a plate cylinder. Here, in the pattern forming apparatus, the letterpress plates of the first and second pattern forming units are replaced according to a pattern to be formed on the substrate. Accordingly, the position of the letterpress plate provided on the outer peripheral surface of a plate cylinder is slightly changed whenever the letterpress plate is replaced. In the first pattern forming unit, the position of the letterpress plate relative to the reference mark on the outer peripheral surface of the plate cylinder is acquired by a plate cylinder-imaging part immediately before a first pattern is formed on the substrate. Accordingly, a deviation from an ideal position is acquired.
JP2014-61653A discloses a letterpress printing apparatus that prints a pattern on a printing target substrate by using a letterpress plate. The letterpress printing apparatus disclosed in JP2014-61653A includes printing means and pattern check means. The printing means includes a letterpress plate, a plate cylinder on which the letterpress plate is mounted on the surface thereof, an ink supply unit that supplies ink to the surface of the letterpress plate, and a moving platen on which a substrate is placed and which transports the substrate. The pattern check means includes a check roller that is included in a moving mechanism of the moving platen and a check unit that checks a pattern printed on the check roller. In JP2014-61653A, ink is transferred to the check roller from the plate cylinder and the outer peripheral surface of the check roller is imaged to check the pattern, so that defects of an ink pattern caused by a defect and the like of the plate are detected before printing is performed on the substrate or the like.
An image forming apparatus disclosed in JP2010-91965A has a function to transport continuous-form paper, on which an image is formed with oil-based ink and which is carried in, by a transport roller, a function to form an image on the continuous-form paper by a printer unit, and an ink half-dry detection function to detect the half dry of ink on the image-formation surface of the continuous-form paper by an ink transfer detecting unit when offset printing processing and printer printing processing are performed.
The ink transfer detecting unit is provided with a CCD (charge-coupled device) sensor that images the surface of an ink transfer roller, a pressure roller that allows the continuous-form paper to be in pressure contact with the peripheral surface of the ink transfer roller, and a stepping motor that allows the pressure roller to reciprocate in the direction of an arrow E. In regard to the half dry of ink, the image-formation surface of the continuous-form paper is made to be in pressure contact with the peripheral surface of the ink transfer roller by the pressure roller, and the CCD sensor detects whether or not oil-based ink adheres to the peripheral surface of the ink transfer roller.